Improving the predictability of intraocular lens power calculations
J. T. Holladay, T. C. Prager, R. S. Ruiz, J. W. Lewis and H. Rosenthal
We reviewed the intraocular lens power calculations on 512 posterior
chamber lens implantations and determined four ways to reduce the estimated
5% incidence of large postoperative refractive "surprises" (greater than 2
diopters [D]): First, preoperatively identify those patients who have
greater than a 1-D difference between the theoretical and linear regression
formulas. Second, repeat axial length and corneal power measurements in
these patients to eliminate random error. Third, develop an individualized
theoretical formula that accounts for constant bias. Fourth, encourage
manufacturers to improve instrumentation for measuring corneal power and
axial length. We also examined the disparity between the linear regression
formula and the curvilinear theoretical formula.
